Hypnea musciformis (Wulfen in Jacqu.) J. V. Lamour. is a native source of kappa-carrageenan, a commercially important galactan, exploited for decades on the northeastern Brazilian coast. Further studies to obtain information about the effects of abiotic factors on the carrageenan yield and quality of specimens from the southeastern Brazilian coast (Rio de Janeiro State) are needed. In this study, the carrageenan yield and quality of H. musciformis was analyzed over a period of 1 year in populations from Rio de Janeiro state. One epiphytic population was collected at a site situated at the entrance of the Sepetiba Bay (Praia Vermelha), another in the middle of the bay (Praia Grande) and a third (Praia Rasa) in a place exposed to the open sea. An epilithic population was also collected at Praia Rasa. In the sampling period, different changes were observed in the carrageenan yield and quality (viscosity and sulphate content) of the H. musciformis (August 1994 to June 1995 at the different sites and habitats (epilithic and epiphytic). Kappa carrageenan was the only one of its type detected. Only one population showed a correlation between viscosity and degree of sulphate content. Our analyses suggest that abiotic factors, such as water movement, desiccation stress, low salinity and extreme temperatures, were the main abiotic factors that influenced the changes in carrageenan of the populations studied. Thus, for a rational use of natural beds of H. musciformis, it is desirable to estimate the changes in carrageenan and algal biomass in the place to be exploited.

RESUMO -(Variação espaço-temporal de populações de Hypnea musciformis (Rhodophyta, Gigartinales) na baía de Sepetiba e Armação dos Búzios, RJ, Brasil). Três populações de Hypnea musciforlllis foram analisadas ao longo do Estado do Rio de Janeiro; duas epifíticas, sublitorãneas, localizadas na baía de Sepetiba (município de Mangaratiba) e uma epilítica, litorânea, localizada em praia exposta a mar aberto (praia Rasa, município de Armação de Búzios). Essas populações foram analisadas quanto à produção de biomassa, flora acompanhante e as possíveis interações com alguns fatores ambientais. As biomassas de H. musciformis variaram nos três locais, não havendo padrão sazonal comum. Observou-se que a movimentação de água, insolação, flora acompanhante e a relação entre a epífita e o hospedeiro, Sargassum spp., causaram efeitos diferenciados sobre a produção das biomassas nas diferentes populações.Palavras chave -Hypnea musciformis, carragenófita, sazonalidade, biomassa ABSTRACT -(Spatial and temporal variation ofpopulations of Hypnea musciformis (Rhodophyta, Gigartinales) in the Sepetiba bay and "Armação dos Búzios", RJ, Brazil). Three populations of H. musciformis were analyzed throughout Rio de Janeiro State; two sublittoral epiphytic populations located in the Sepetiba bay (Mangaratiba municipality), and one intertidal epilithic population on the shore facing the open sea (Rasa beach, Armação dos Búzios municipality). These populations were analyzed for seasonality in biomass production, the accompanying flora species, and the possible interactions with some environmental factors. The biomass production of H. lIluscifonnis was different at each site, water movement, sunlight, accompanying flora, and the relation between the epiphyte and host, Sargassum spp., caused different effecls on biomass production in differenl populations.

The carragenophyte Kappaphycus alvarezii has been introduced into tropical regions, including Brazil, for aquaculture purposes. Our study estimated the biomass loss of farmed cuttings, the establishment of cuttings outside the rafts, the occurrence of spores, and evaluated the invasive potential of K. alvarezii at three sites in Rio de Janeiro state. Temperature, salinity, water transparency, wind velocity and direction (hydrodynamic indicator) and solar radiation (irradiance availability indicator) varied spatially. We found no spores in cultivated cuttings and no verified spore recruitment on artificial substrata. Biomass loss of cuttings varied temporally; however, it was restricted to the cultivation management area of one site and was low compared to native algal biomass. The establishment of cuttings was apparently limited by herbivory at Ilha Grande Bay and controlled by water transparency, hydrodynamics and temperature at Sepetiba Bay. The invasive potential of K. alvarezii was considered remote. However, the use of environmental protocols for cultivation activities is necessary to prevent environmental impacts, mainly in tropical regions.

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In vitro cultivation of three Kappaphycus alvarezii (Rhodophyta, Areschougiaceae) variants (green, red and brown) exposed to a commercial extract of the brown alga Ascophyllum nodosum (Fucaceae, Ochrophyta) Abstract Diseases such as "ice-ice" and "goose bumps" are responsible for loss of almost 70% of infected Kappaphycus production. To improve the growth of K. alvarezii and reduce the impact of diseases, the effect of the commercial Ascophyllum nodosum extract was tested. Five grams of apical branches of each K. alvarezii variant (n=6) were bathed at different extract concentrations (e.g., 5, 10, 15, 20, 25, and 30 g L −1 ) for 1 hour. To test the effect of the extract on epiphytes apical tips were not cleaned. After 2 weeks, the epiphytes such as Cladophora sp. and Ulva sp. disappeared. Polysiphonia subtilissima survived but its appearance was weak. The highest K. alvarezii growth rates were observed at extract concentrations of 15 and 20 g L −1 (p<0.001), almost double the expected for a 45-day production cycle used at Sepetiba Bay, Brazil. These results show that the extract was efficient at improving the growth of K. alvarezii and reducing the presence of some epiphytes.

A new cultivation technique for Kappaphycus alvarezii was used in the Brazilian southeastern coast (23°02′25″ S and 43°53′39″ W), the tubular netting on floating rafts. The tubular net technique (TN) was compared with the current method of tie-tie (TT). After 47 days, the daily growth rate (mean±SD of TN and TT=3.4±0.7% day −1 ), carrageenan yield (mean±SD of TN and TT=36± 1.3%), gel strength (mean±SD of TN and TT=730±114.5 g cm²), and viscosity (mean±SD of TN and TT=350±60.4 cP) did not differ between the two techniques (p>0.05). The amount of time used to plant (TT=30.2±2.3 min and TN= 13.3±3.4 min) and to harvest the seedlings (TT=36.2± 2.7 min and TN=17.8±3.7 min) were lower in TN (p< 0.001). It is concluded that TN was more effective than TT, the cultivation management (time rates used to plant and harvest the seedlings) was 53.6% faster, no seedlings were lost, the cost was lower, and an estimated return in 1 year of nearly 20% more than that of the TT technique.

-(Characterisation of macroalgae in the marine communities of Cairuçú Environmental Protected Area, Parati, RJ -bases for future monitoring). Macroalgae can be used to indicate biological and physical disturbances in the environment. In this study, the phyto-benthic community structure served to characterise the Cairuçú Protected Area. Six sampling sites represented a variety of environmental conditions inside Parati Bay, RJ. The most wave-exposed site was Ponta da Cajaíba followed by moderately exposed Praia da Conceição, and all the other sites were sheltered. Quali-and quantitative sampling of macroalgae were carried out four times a year. Algal cover was estimated within functional-form groups in the sublittoral zone using 10 m transects, each one with 10-30 random quadrats of 0.04 m 2 . Density of herbivorous sea urchins was estimated within 10 areas of 0.25 m 2 . There were 15 taxa added to the marine flora of Parati district, making a total of 136 taxa. Comparing local floras in southern areas of Rio de Janeiro State, Parati was similar to both Sepetiba Bay and the remaining of Ilha Grande Bay. Ilha Comprida, Saco da Velha, Praia Vermelha and Ponta do Buraco were dominated by corticated, coriaceous and articulated calcareous erect algae showing a lower cover of crustose calcareous algae. Sargassum dominated in more stable environmental conditions being replaced by smaller rhodophytes after its senescent phase, suggesting competition for stratum space. Places more exposed to waves and/or herbivores (Praia da Conceição and Ponta da Cajaíba) were dominated by crustose and small erect algae, in agreement with algae abundance patterns predicted by form and function models dependent on degrees of physical and biological disturbance.Key words -APA Cairuçú, distribution, functional-form groups, macroalgae, physical and biological disturbances RESUMO -(Caracterização das macroalgas nas comunidades marinhas da Área de Proteção Ambiental de Cairuçú, Parati, RJsubsídios para futuros monitoramentos). As macroalgas podem ser usadas para indicar distúrbios biológicos e físicos do ambiente. Neste estudo, a estrutura das comunidades fitobentônicas serviu para caracterizar a Área de Proteção Ambiental de Cairuçú. Seis locais de coleta representaram diversas condições ambientais dentro da Baía de Parati, RJ. O local mais exposto às ondas foi a Ponta da Cajaíba, seguido pela Praia da Conceição, moderadamente exposta às ondas, e os demais foram protegidos. Coletas quali e quantitativas das macroalgas foram realizadas em quatro épocas do ano. A cobertura destas foi estimada em grupos morfo-funcionais no sublitoral em transectos de 10 m, cada um com 10-30 quadrados aleatórios de 0,04 m 2 . A densidade dos ouriços herbívoros foi estimada em 10 áreas de 0,25 m 2 . Foram acrescidos 15 táxons à flora do Município de Parati, totalizando 136. Na comparação entre floras do sul fluminense, Parati assemelha-se ao grupo da Baía de Sepetiba e o restante da Baía da Ilha Grande. A Ilha Comprida, Saco da Velha, Praia Vermelha e Pont...